1. Field of the Invention
The present invention relates to an upper plate of plasma display panel, and a manufacturing method thereof. Particularly, the present invention relates to a black paste composition capable of improving the property of a black matrix, and a plasma display panel using the same.
2. Description of the Related Art
Plasma display panel (PDP) is a flat panel display device that can display images or information by using a light-emitting phenomenon from plasma discharge. PDP is generally divided into DC-type and AC-type according to panel structure and driving method.
PDP generates plasma discharge in each cell separated by barrier ribs. Thus, PDP is a display device using the light emitting phenomenon of visible rays generated from the energy difference when ultraviolet rays generated by plasma discharge of a gas (such as He, Xe, etc.) provided in each cell returns to the ground state by exciting a phosphor in the cell.
PDP has several advantages such as simple structure, easy manufacturing due to simple structure, high brightness, high luminous efficacy, memory capacity effect, and a wide viewing angle over 160°. Also, PDP can be used for wide screens of 40 or more inches.
FIGS. 1A-1F are cross-sectional views illustrating the steps of forming the upper plate of a common PDP in the art.
First, as shown in FIG. 1A, a black paste composition 122 is applied on an upper substrate 100 at the state that a transparent electrode 110 consisted of ITO, etc. is already formed by a process, for example, sputtering, ion plating, chemical depositing or electrodepositing.
The black paste composition 122 is RuO compound.
Then, an electrode material 132 is applied as shown in FIG. 1B.
Subsequently, a first mask 160 having a certain opening 162 is disposed on the upper substrate 100 on which the electrode material 132 is applied. The first mask 160 has the opening 162 at a position corresponding to a bus electrode 130, as shown in FIG. 1C.
The first mask was exposed to light by irradiating a UV lamp from top of the first mask 160 for a certain period of time.
Then, after the first mask 160 is removed, the upper substrate 100 is developed by using a developer.
As a result, the electrode material 132 and the black paste composition 122 in the other parts are removed, with only leaving cured parts in response to the UV lamp, as shown in FIG. 1D. Then, a sintering process is carried out thereto.
And, a dielectric layer material is applied on the upper substrate 100 on which the first black matrix 120 and the bus electrode 130 are formed, and dried to form an upper dielectric layer 140, as shown in FIG. 1E.
Then, the black paste composition 122 is re-applied on top of the upper dielectric layer 140. A second black matrix 150 is formed in each discharge cell through performing the developing and sintering processed thereto, as shown in FIG. 1F.
Subsequently, the manufacturing process of the upper plate of PDP is completed through forming one more dielectric layer (not shown) or a protection layer (not shown), on top of the upper dielectric layer 140 on which the second black matrix 150 is formed.
In case of manufacturing the upper plate of PDP through the above steps, the first and second black matrixes 120 and 150 are formed through two steps. That is, to form the first black matrix 120 disposed between the transparent electrode 110 and the bus electrode 120, the black paste composition 122 is applied, and the light-exposing, developing, and sintering processes are followed.
Also, to form the second black matrix 150 disposed in each discharge cell, the black paste composition 122 is applied, and the light-exposing, developing, and sintering processes are followed.
Thus, the manufacturing process becomes complicated, and the manufacturing cost as well as the manufacturing time is increased.
Also, the RuO compound used as the black paste composition 122 is very expensive, thereby increasing the manufacturing cost.